Yes Delpha, it's not as well known but it is really nice. It's newer than Napa and Sonoma so you'll find some fantastic tasting rooms since they were built later. And it's easy to get to the wineries without long drives.
Victoria, we didn't find them crowded at all. However, we did hear that some can be crowded on the weekends. But if you have to wait, there are 40 more wineries you can visit. :)